progress by means of hops, and aid themselves with their wings. Many of the Falconidae are very quarrelsome, and use their talons as weapons of offence, this trait being emphasized at the nesting-quarters, whence feathered intruders are rigorously excluded. The cry is shrill, but varies in depth; in the Peregrine Falcon it is a succession of short notes, in Eagles it resembles a yelp, in Buzzards a cat's mew, in Kites a whistle, and so forth; whereas in _Melierax_ it may almost be called a song. The diet varies considerably, and consists of mammals, birds, reptiles, fish, frogs, tortoises, crabs, molluscs, and insects. _Gypohierax_, _Aquila_, _Haliastur_, _Milvago_, and _Polyborus_ certainly eat carrion, and the last will attack newly-born lambs–a grievance made the most of by sheep-farmers in the case of Eagles; while the larger forms kill fawns, monkeys, foxes, hares, and other creatures of considerable size. Buzzards keep down rabbits, and hunt rats and mice as assiduously as Harriers and the Kestrel; the latter devours quantities of insects, as do also some of the Polyborinae; and the so-called "Honey" Buzzard (_Pernis_) gains its name from its fondness for grubs of bees or wasps. Kites work havoc among poultry; the Golden Eagle, and still more the Peregrine Falcon, among moor-fowl; the last two proving an {149}advantage in Scotch deer-forests, where the noisy grouse disturb the stags, but being in peril of extermination on the moorlands; yet it is questionable whether more good than harm is not done by the destruction of weakly game. The Osprey and Sea-Eagle eat little but fish, though they are not alone in that habit, while _Rostrhamus_ lives almost entirely on fresh-water molluscs. Most members of the Family do not alight to capture their prey, but seize it with their sharp talons either sitting or on the wing, the chief exceptions being the carrion- and insect-eaters; it is often conveyed to some favourite spot of ground or rock to devour, smaller objects being transported in the bill and the bigger torn to pieces and stripped before being swallowed. Large bones may be broken up, slender bones bolted entire; but hard substances are always ejected subsequently as pellets, after the manner of Owls (p. 401), the nature of the diet being readily detected from these castings. Exceptionally curious habits are credited to _Gypaëtus_ and _Gypoictinia_, as will be seen below. After a meal, quiescence is the rule, but none of the tribe gorge like Vultures. The predilections of species or even of individuals determine the situation of the nest, Eagles and other large forms preferring rocks in mountain-glens, lofty cliffs, or trees, for their bulky fabric of sticks, heather, and the like, which is lined with softer substances, and often bedded with foliage. The larger Falcons frequently select ledges on sea-girt or inland crags, and merely scrape a hole in the soil; but they, in common with the lesser Falcons, also utilize